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1.2 – Describe vCenter Server topology

The vCenter Server is deployed as a self-contained appliance or VCSA and all services run in a single machine. This opposed to the previous versions of vcenter which created an external platform services controller PSC.

If you are upgrading to the latest version of vCenter you can use a tool called vCenter Server Converge Tool which migrates the external PSCs into the embedded ones. Migrating Windows-based vCenters comes in a two-stage process.

  1. You’ll first need to deploy a new vCenter Server
  2. You’ll need to copy the data from the source vCenter to the newly deployed vCenter

The vCenter Server architecture relies on the following components:

  • VSphere Client: You use this client to connect to vCenter Server so that you can manage your ESXi hosts centrally
  • VCenter Server database: The vCenter Server database is the most important component. The database stores inventory items, security roles, resource pools, performance data and other critical information for vCenter Server
  • Managed hosts: You can use vCenter Server to manage ESXi hosts and the VMs that run on them.

The vCenter server is an appliance package which comes with the following software:

  • The vSphere authentication services
  • Photon OS 3.0
  • PostgreSQL
  • VMware vSphere Lifecycle Manager Exension
  • VMware vCenter Lifecycle Manager

There are several authentication services which are present in the vCenter server:

  • vCenter SSO
  • VMware directory Services
  • Security Token Service
  • vCenter lookup Service
  • vSphere License Service
  • VMware Certificate Authority

There are also several services which are automatically installed with vCenter Server

  • vSphere client
  • vSphere ESXi dump collector
  • vSphere Auto Deploy
  • vCenter Server plug-ins
  • tcServer

A vSphere installation typically consists of several devices and services. If we contain them somewhat to the scope of the exam, we can conclude that a typical datacenter consists of one or multiple ESXi host(s), storage networks or / and arrays, IP networks, a vCenter server and several management clients.